#include<iostream>
#include<string>

using namespace std;

int main(){

	string s1;

	s1="Hello woooorld";
	cout<<s1.find("oooo")<<endl;


	cout<<(int)s1.find("oooo",8)<<endl;
	if((int)s1.find("oooo",8)==-1) cout<<"真的没找到啊！！！"<<endl;



	cout<<s1.find('o')<<endl;
	cout<<s1.find('o',s1.find('o')+1)<<endl;



	cout<<"从右向左去寻找的"<<endl;
	cout<<s1.rfind('o')<<endl;	
	return 0;

}
